1. Field of the Invention
The present invention relates to a device for charging a measuring apparatus for thermal analysis with material specimens or samples filled into containers. The device includes a revolving specimen plate or turntable with cutouts or recesses for receiving the specimen containers and means for gripping, lifting and transferring each container from the specimen plate to a measuring location in the measuring apparatus.
2. Description of the Related Art
Thermal analysis in the narrow sense includes methods of examining materials as a function of temperature, for example, differential thermal analysis (DTA), differential scanning calorimetry (DSC) and thermal gravimetry (TG).
In a broader sense, thermal analysis could also include methods of determining the dry substance or moisture contents of material specimens.
For carrying out measurements on large quantities of specimens of the same type, it is desirable and known in the art to mechanize the manipulation of the specimens partially or entirely by means of charging devices. For example, DE-A1-4023483 discloses an apparatus for dry substance determination in which the specimens are arranged on a turntable within a microwave oven. The weighing dish of the balance is also located within the microwave oven underneath the turntable. The specimens are positioned above openings in the turntable and can be placed individually on the weighing dish by lowering the turntable, so that the weighing dish extends through the opening in the turntable located above the weighing dish. The specimens are picked up again in the reverse sequence.
The known apparatus described above has the disadvantage that all specimens are located within the oven and, therefore, the oven must be opened for charging it with new specimens. In addition, the oven must be very large. A further disadvantage of the known apparatus is to be seen in the fact that the person operating the apparatus does not have an opportunity to observe the apparatus during operation to see whether the specimens are correctly placed on the weighing dish.
DE-A1-3814959 discloses a hygrometer with a specimen changer. The specimens are also placed on a turntable which is provided with openings arranged in a circle. The turntable and the weighing dish of the balance are arranged within the drying chamber and, therefore, are not accessible during measurements.